/*
struct TreeNode {
	int val;
	struct TreeNode *left;
	struct TreeNode *right;
	TreeNode(int x) :
			val(x), left(NULL), right(NULL) {
	}
};*/
class Solution {
public:
    int TreeDepth(TreeNode* pRoot) {
        if(pRoot == nullptr) return 0;
        //在当前结点的左右子树的深度基础上加1
        return ( TreeDepth(pRoot->left)>TreeDepth(pRoot->right)?
               TreeDepth(pRoot->left):TreeDepth(pRoot->right) ) + 1;
    }
};